In this question we compare two ways of handling precision within calculations. The first method involves simply counting the number of significant figures, while the second method uses the rules for calculating the absolute uncertainty. As we shall see, the second method is a lot better than the first.
Suppose that m1 = 3.2 g and m2 = 0.07 g.

a. Calculate m1 + m2 and give your answer to an appropriate number of significant figures.

b. Does this value seem reasonable? Why or why not?

c. Assuming that each measurement comes with the usual uncertainty (half of the next decimal place), calculate the absolute uncertainty in m1 + m2.

d. Which method makes more sense?